Desarrollo de la seguridad y actividades mediatizantes : el caso del trabajo en la construcción

1. Problemática : Mejorar la seguridad en las obras de construcción Una constructora de tamaño mundial solicitó el equipo clínica de la actividad en 2004 para buscar nuevas formas de pensamiento y de acción con el fin de reducir el número de accidentes en obras de la construcción y más generalmente, para mejorar la seguridad del trabajo. El grupo teme de que aumente la tasa de frecuencia de accidentes [] estancado en alrededor de 25 accidentes por cada millón de horas trabajadas desde la déc..

Fabrication de sondes à ARN biotinylées à partir d’ADN de sang complet de macaques à crête (Macaca nigra) afin d’étudier la parenté dans les populations sauvages

Comment rendre plus efficiente l’analyse génétique de la parenté des primates en milieu naturel par rapport à l’utilisation de marqueurs microsatellites et comment générer des données génétiques à l’échelle du génome dans le but d’étudier l’histoire évolutive de ces animaux sauvages ? Sur le terrain, l’échantillonnage se veut non invasif et les fèces fournissent un ADN dégradé, en faible quantité et contaminé avec de l’ADN environnemental, avec seulement ~1 % de l’ADN contenu dans les extrai..

Linking parasitism to network centrality and the impact of sampling bias in its interpretation

Group living is beneficial for individuals, but also comes with costs. One such cost is the increased possibility of pathogen transmission because increased numbers or frequencies of social contacts are often associated with increased parasite abundance or diversity. The social structure of a group or population is paramount to patterns of infection and transmission. Yet, for various reasons, studies investigating the links between sociality and parasitism in animals, especially in primates, have only accounted for parts of the group (e.g., only adults), which is likely to impact the interpretation of results. Here, we investigated the relationship between social network centrality and an estimate of gastrointestinal helminth infection intensity in a whole group of Japanese macaques (Macaca fuscata). We then tested the impact of omitting parts of the group on this relationship. We aimed to test: (1) whether social network centrality –in terms of the number of partners (degree), frequency of interactions (strength), and level of social integration (eigenvector) –was linked to parasite infection intensity (estimated by eggs per gram of faeces, EPG); and, (2) to what extent excluding portions of individuals within the group might influence the observed relationship. We conducted social network analysis on data collected from one group of Japanese macaques over three months on Koshima Island, Japan. We then ran a series of knock-out simulations. General linear mixed models showed that, at the whole-group level, network centrality was positively associated with geohelminth infection intensity. However, in partial networks with only adult females, only juveniles, or random subsets of the group, the strength of this relationship - albeit still generally positive - lost statistical significance. Furthermore, knock-out simulations where individuals were removed but network metrics were retained from the original whole-group network showed that these changes are partly a power issue and partly an effect of sampling the incomplete network. Our study indicates that sampling bias can thus hamper our ability to detect real network effects involving social interaction and parasitism. In addition to supporting earlier results linking geohelminth infection to Japanese macaque social networks, this work introduces important methodological considerations for research into the dynamics of social transmission, with implications for infectious disease epidemiology, population management, and health interventions

Higher social tolerance is associated with more complex facial behavior in macaques

The social complexity hypothesis for communicative complexity posits that animal societies with more complex social systems require more complex communication systems. We tested the social complexity hypothesis on three macaque species that vary in their degree of social tolerance and complexity. We coded facial behavior in >3000 social interactions across three social contexts (aggressive, submissive, affiliative) in 389 animals, using the Facial Action Coding System for macaques (MaqFACS). We quantified communicative complexity using three measures of uncertainty: entropy, specificity, and prediction error. We found that the relative entropy of facial behavior was higher for the more tolerant crested macaques as compared to the less tolerant Barbary and rhesus macaques across all social contexts, indicating that crested macaques more frequently use a higher diversity of facial behavior. The context specificity of facial behavior was higher in rhesus as compared to Barbary and crested macaques, demonstrating that Barbary and crested macaques used facial behavior more flexibly across different social contexts. Finally, a random forest classifier predicted social context from facial behavior with highest accuracy for rhesus and lowest for crested, indicating there is higher uncertainty and complexity in the facial behavior of crested macaques. Overall, our results support the social complexity hypothesis

Degrees of freedom in social bonds of crested macaque females

Social bonds between group members can affect individual fitness and well-being. While the impact of bond strength is well studied, the consequences of bond predictability and equitability are often overlooked. Similarly, whether bonds reflect short-term contingencies and/or long-term social strategies remains understudied. We investigated these questions in female crested macaques (Macaca nigra), which display a tolerant social style within a nepotistic hierarchical social structure. We analysed the structure of dyadic social bonds by testing whether similarity within dyads - in kinship, dominance and age - predicted the strength, predictability and equitability of bonds. We then tested the value of social bonds by analysing the effect of their characteristics on three fitness-related behaviours: coalitionary support, feeding-in-proximity and aggression. We found that the bond characteristics of females differed substantially from those of other species with comparable data: bonds were of average strength, of moderate endurance and relatively balanced. Stronger bonds were more equitable but less predictable than weaker bonds. Closely-ranked females, but not kin or age peers, had stronger, more predictable and more equitable bonds than others. Coalitionary support was not related to any of the bond characteristics, feeding-in-proximity was positively associated with strength and predictability and aggression was positively linked to strength and equitability. These results highlight the complex picture of the benefits of social bonds in this species. They reflect the degrees of freedom tolerant macaque females can express in their social relationships within their stable social structure, a pattern that may not be given enough consideration in stable nepotistic hierarchical societies. Comparative research is necessary to establish whether these patterns are more general than previously thought or a specific feature of tolerant macaques. Investigating various characteristics of bonds together is paramount in order to appreciate the dynamics of social relationships and to better understand the social components of fitness

Assessing dominance hierarchies: validation and advantages of progressive evaluation with Elo-rating

Highlights ► Elo-rating generates reliable dominance hierarchies and circumvents drawbacks of established ranking methods. ► It allows visualizing dominance relationships and the detection of rank dynamics. ► An index to objectively assess the stability of a dominance hierarchy is proposed

Sex and dominance: How to assess and interpret intersexual dominance relationships in mammalian societies

The causes and consequences of being in a particular dominance position have been illuminated in various animal species, and new methods to assess dominance relationships and to describe the structure of dominance hierarchies have been developed in recent years. Most research has focused on same-sex relationships, however, so that intersexual dominance relationships and hierarchies including both sexes have remained much less studied. In particular, different methods continue to be employed to rank males and females along a dominance hierarchy, and sex biases in dominance are still widely regarded as simple byproducts of sexual size dimorphism. However, males and females regularly compete over similar resources when living in the same group, and sexual conflict takes a variety of forms across societies. These processes affect the fitness of both sexes, and are mitigated by intersexual hierarchies. In this study, we draw on data from free-ranging populations of nine species of mammals that vary in the degree to which members of one sex dominate members of the other sex to explore the consequences of using different criteria and procedures for describing intra- and intersexual dominance relationships in these societies. Our analyses confirmed a continuum in patterns of intersexual dominance, from strictly male-dominated species to strictly female-dominated species. All indices of the degree of female dominance were well correlated with each other. The rank order among same-sex individuals was highly correlated between the intra- and intersexual hierarchies, and such correlation was not affected by the degree of female dominance. The relative prevalence of aggression and submission was sensitive to variation in the degree of female dominance across species, with more submissive signals and fewer aggressive acts being used in societies where female dominance prevails. Thus, this study provides important insights and key methodological tools to study intersexual dominance relationships in mammals

Social tolerance : novel insights from wild female crested macaques, Macaca nigra

La socialité diverse des femelles primates reflète une combinaison de stratégies compétitives et coopératives. Différentes théories expliquent cette diversité. Les macaques sont un bon exemple de variation sociale. L’objectif de ma thèse est d’approfondir la connaissance des sociétés de macaques par l’étude d’une espèce peu connue, les macaques à crête, Macaca nigra, dans son milieu naturel, la réserve de Tangkoko à Sulawesi, Indonésie. 2600 heures de données comportementales ont été prises sur 42 femelles adultes d’Octobre 2008 à Juin 2010. En combinant une analyse compréhensive des variables comportementales, je confirme le style social tolérant des femelles. En examinant la fonction des interactions post-agression par l’analyse des liens entre agression, anxiété, caractéristiques des conflits et de celles des dyades impliquées et les interactions post-agression, je détermine que celles-ci ne servent pas à réduire l’anxiété ou à “raccommoder” les relations sociales mais fonctionnent plutôt pour signaler l’intention pacifique ou pour réaffirmer le statut social. En étudiant l’influence des relations de dominance et de parenté sur les interactions sociales, je détermine que la force des liens sociaux n’est pas forcement liée a la dominance ou la parenté et que les coalitions sont formées entre femelles proches en dominance, mais pas entre apparentées ou proches affiliées. Ces résultats contrastent avec d’autres sociétés animales et mettent en évidence la complexité des sociétés tolérantes. Ma thèse apporte de nouvelles bases empiriques sur la variation sociale dans une perspective comparative et apporte un nouveau cadre théorique sur l’évolution des sociétés animales.The diversity in female primate sociality reflects a combination of competitive and cooperative strategies. Different frameworks explain such diversity. The genus Macaca is a good example of social variation. The aim of my thesis is to foster our understanding of macaque societies by studying one little-known species, the crested macaque, Macaca nigra, under natural conditions, the Tangkoko Reserve, in Sulawesi Indonesia. From October 2008 to June 2010, I gathered 2600 hours of behavioural data on 42 adult females. By quantifying a comprehensive set of behaviours, I confirm the females’ tolerant social style. I investigate the function of post-conflict interactions by analysing the relationship between aggression, anxiety, characteristics of conflicts, of dyads involved in conflicts, and the occurrence of post-conflict interactions. Post-conflict interactions did not serve to reduce stress or to “repair” relationships but function as a signal of benign intent or to reassert social status. I analyse the hierarchical and nepotistic influence on social relationships and show that social bonds are not entirely shaped by kinship or dominance. Coalitionary support occurred amongst females close in rank but not amongst close kin or strong affiliates. These patterns represent meaningful contrasts to other animal species and highlight the complexity of social life in tolerant societies. By combining behavioural and genetic data, my thesis brings an empirical basis to theoretical frameworks on the evolution of social diversity, reflects on the interplay between different factors in a comparative perspective and provides a general framework for the evolution of animal societies

Nouvelles perspectives sur la tolérance sociale à travers l'étude des femelles macaque à crête, Macaca nigra, dans leur milieu naturel

The diversity in female primate sociality reflects a combination of competitive and cooperative strategies. Different frameworks explain such diversity. The genus Macaca is a good example of social variation. The aim of my thesis is to foster our understanding of macaque societies by studying one little-known species, the crested macaque, Macaca nigra, under natural conditions, the Tangkoko Reserve, in Sulawesi Indonesia. From October 2008 to June 2010, I gathered 2600 hours of behavioural data on 42 adult females. By quantifying a comprehensive set of behaviours, I confirm the females’ tolerant social style. I investigate the function of post-conflict interactions by analysing the relationship between aggression, anxiety, characteristics of conflicts, of dyads involved in conflicts, and the occurrence of post-conflict interactions. Post-conflict interactions did not serve to reduce stress or to “repair” relationships but function as a signal of benign intent or to reassert social status. I analyse the hierarchical and nepotistic influence on social relationships and show that social bonds are not entirely shaped by kinship or dominance. Coalitionary support occurred amongst females close in rank but not amongst close kin or strong affiliates. These patterns represent meaningful contrasts to other animal species and highlight the complexity of social life in tolerant societies. By combining behavioural and genetic data, my thesis brings an empirical basis to theoretical frameworks on the evolution of social diversity, reflects on the interplay between different factors in a comparative perspective and provides a general framework for the evolution of animal societies.La socialité diverse des femelles primates reflète une combinaison de stratégies compétitives et coopératives. Différentes théories expliquent cette diversité. Les macaques sont un bon exemple de variation sociale. L’objectif de ma thèse est d’approfondir la connaissance des sociétés de macaques par l’étude d’une espèce peu connue, les macaques à crête, Macaca nigra, dans son milieu naturel, la réserve de Tangkoko à Sulawesi, Indonésie. 2600 heures de données comportementales ont été prises sur 42 femelles adultes d’Octobre 2008 à Juin 2010. En combinant une analyse compréhensive des variables comportementales, je confirme le style social tolérant des femelles. En examinant la fonction des interactions post-agression par l’analyse des liens entre agression, anxiété, caractéristiques des conflits et de celles des dyades impliquées et les interactions post-agression, je détermine que celles-ci ne servent pas à réduire l’anxiété ou à “raccommoder” les relations sociales mais fonctionnent plutôt pour signaler l’intention pacifique ou pour réaffirmer le statut social. En étudiant l’influence des relations de dominance et de parenté sur les interactions sociales, je détermine que la force des liens sociaux n’est pas forcement liée a la dominance ou la parenté et que les coalitions sont formées entre femelles proches en dominance, mais pas entre apparentées ou proches affiliées. Ces résultats contrastent avec d’autres sociétés animales et mettent en évidence la complexité des sociétés tolérantes. Ma thèse apporte de nouvelles bases empiriques sur la variation sociale dans une perspective comparative et apporte un nouveau cadre théorique sur l’évolution des sociétés animales

"How social transmission can inform about the costs and benefits of sociality"

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